// storage封装
const STORAGE_KEY ='mall'
export default{
  // 存储值
  setItem(key,value,module_name){
    if(module_name){
      let val = this.getItem(module_name)
      val[key] =value
      this.setItem(module_name,val)
    }else{

      let val =this.getStorge();
      val[key]=value
      window.sessionStorage.setItem(STORAGE_KEY,JSON.stringify(val))
    }

  },
  //获取某一个模块下面的属性user下面的userName
  getItem(key,module_name){
    if(module_name){
      let val = this.getItem(module_name)
      if(val)return val[key]
    }
    return this.getStorge()[key]
  },
  getStorge(){
  return  JSON.parse(window.sessionStorage.getItem(STORAGE_KEY) || '{}')   
  },
  clear(key,module_name){ 
    let val=this.getStorge();
    if(!val[module_name]) return
    if(module_name){
      delete val[module_name][key]

    }else{
      delete val[key]
    }
    window.sessionStorage.setItem(STORAGE_KEY,JSON.stringify(val))
  },
}